This application claims the priority date of Apr. 18, 2000 for Japanese Patent Application No. 2000-116261.
1. Field of the Invention
This invention generally relates to a mist discharger. More particularly, this invention relates to a self-adjusting oil mist discharger.
2. Background Art
Conventionally, cutting oil such as lubricant is sprayed or dropped onto a cutting/drilling portion of a metallic or synthesized resin material being machined for lubrication and/or cooling so as to provide smooth cutting, prevent heat generation and eliminate damage to the cutting/drilling tool and the object material under treatment.
Of late, attempts have been made to reduce the amount of cutting oil used in cutting/drilling operations in order to reduce machining costs by saving on cutting oil and more importantly in consideration of the environmental preservation. Used cutting oil is conventionally treated in a costly way for recycling or disposal or simply disposed of in the nature.
A most desirous way to save on cutting oil without adversely affecting cutting or drilling operations is to discharge cutting oil in a mist form. In order to optimally provide an oil mist with conventional oil mist dischargers, very fine and delicate adjustment of the discharge performance is indispensable.
Conventionally, very time-consuming and highly burdensome manual adjustment of oil mist discharge performance is required every time cutting/drilling tools or discharge nozzles are changed for particular objects to be machined or for desired machining dimensions. Simplification of such adjustments in a conventional way may be possible, however not without unacceptably costly adjustment devices or complication of the whole systems.
If the adjustment of the conventional oil mist discharger is inappropriate, excessive or insufficient oil or lubricant in an inadequately formed mist will be discharged. Ordinary artisans in the relevant art know well that discharging of optimal oil mists requires highly sophisticated technology and know-how.
Accordingly, it is an object of the present invention to provide a mist discharger which is self-controlled and discharges optimal mists.
It is another object of the present invention to provide an oil mist discharger for use with a cutting/drilling tool which automatically adjusts itself corresponding to the caliber of a discharge nozzle used.
It is another object of the present invention to provide an oil mist discharger which discharges an oil mist which is optimally blended with air stream.
It is another object of the present invention to provide an oil mist discharger which is far more reliable than conventional oil mist dischargers.
It is still another object of the present invention to provide an oil mist discharger at a lower manufacturing cost than conventional oil mist dischargers by simplifying the overall structure.
Accordingly it is yet another object of the present invention to provide an oil mist discharger which requires less maintenance work than conventional oil mist dischargers.
It is another object of the present invention to provide novel flow regulating means for use in an oil mist discharger which automatically provides an optimal oil mist in accordance with the caliber of the nozzle.
It is still another object of the present invention to provide novel oil pressure regulating means for use in an oil mist discharger.
Other objects of the present invention will become apparent from the descriptions that follow, and those and other objects of the present invention are attained with an oil mist discharger of the present invention.
An oil mist discharger of the present invention is utilized with a cutting or drilling tool to machine objects such as metallic or plastic materials. The oil mist discharger provides a mist stream of lubricant or cutting oil onto the cutting/drilling spot of the object being machined most effectively and optimally. Insufficient or excessive provision of cutting oil in inappropriate oil particle sizes is avoided as the oil mist discharger of the present invention is provided with a self-adjusting mechanism to automatically discharge an optimal amount of cutting oil in an optimal mist form.
The oil mist discharger of the present invention utilizes a novel flow regulator of a compact size, which effectively and efficiently utilizes the differential pressure between air pressure and oil pressure so as to optimally draw cutting oil from an oil tank into air and optimally blend the introduced cutting oil with the air for discharging from the discharge nozzle against a cutting or drilling tool or against a machining spot. Such functions are provided in an automatic manner.
The flow regulator of the present invention comprises a main passage which is diverged into a plurality of sub-passage units at a plurality of locations. The sub-passage units are provided with different lengths. The main passage is substantially larger than the sub-passages in diameter. Each unit consisting of two sub-passages is forked from the main passage generally at right angles to the xe2x80x9crightxe2x80x9d and xe2x80x9cleft,xe2x80x9d having two identical openings.
Those two openings face each other across the main passage. The sub-passage units are provided on the main passage at different distances from the closed forward end of the main passage. Each unit of the xe2x80x9crightxe2x80x9d and xe2x80x9cleftxe2x80x9d sub-passages forms a generally xe2x80x9ccircularxe2x80x9d configuration, which is connected to an agitation chamber, where the oil-containing air streams coming in through the sub-passages converge and optimal agitation is provided so as to produce an optimally blended oil mist. The circular sub-passage units have different radii from one another.
The oil-containing air stream coming in through the main passage meets the closed forward end of the main passage, where the pressurized oil-containing air makes headway toward the openings of the sub-passages. When the air velocity is xe2x80x9chighxe2x80x9d (when the caliber of the discharge nozzle is xe2x80x9clargexe2x80x9d), the oil-containing air stream will enter substantially all sub-passage units, however, when the air velocity is xe2x80x9clowxe2x80x9d (when the caliber of the discharge nozzle is xe2x80x9csmallxe2x80x9d), the oil-containing air stream will enter substantially fewer units of sub-passages which are closer to the forward end of the main passage.
It is an accepted theory that the higher the velocity of a fluid in a pipe, the lower the fluid pressure. It is to be noted that the velocity of the oil-containing air stream flowing through the main passage is a factor of the caliber of the discharge nozzle. Therefore, when the caliber of the discharge nozzle is xe2x80x9clarge,xe2x80x9d the air pressure in the main passage is xe2x80x9clow,xe2x80x9d and when the caliber of the discharge nozzle is xe2x80x9csmall,xe2x80x9d the air pressure in the main passage is xe2x80x9clarge.xe2x80x9d
Cutting oil to be supplied in an airflow is drawn into the air stream through an oil outlet which is provided very close to the main passage or practically within the main passage by utilization of the differential pressure between the oil pressure in the built-in oil tank and the air pressure of the air stream. The lower the air pressure is (when the caliber of the discharge nozzle is large), the greater the differential pressure and the more oil is drawn into the air stream to provide a thicker oil mist in the agitation chamber.
When the caliber of the nozzle is xe2x80x9clarge,xe2x80x9d more cutting oil is blended in the air stream. The air stream carrying xe2x80x9cmuchxe2x80x9d oil comes out of all or a plurality of the sub-passage units into the agitation chamber in xe2x80x9cfinexe2x80x9d jet streams, facilitating excellent blending of the cutting oil and air in the agitation chamber into a micro particle oil mist. On the other hand, when the caliber of the nozzle is xe2x80x9csmall,xe2x80x9d a well blended micro particle oil mist is provided in the agitation chamber.
The oil pressure in the built-in oil tank is also regulated with a novel oil pressure regulator of the present invention and is held greater than the air pressure in the main passage or in the vicinity of the oil outlet when the oil mist discharger is in use, as will be readily appreciated by an ordinary artisan in the relevant art.
The oil pressure regulator of the present invention comprises a ball, O-ring, coil spring and oil cap having a leg. The airtightness between the O-ring and the ball is regulated with the oil cap and the coil spring.
The oil mist discharger of the present invention comprises other conventional devices and members including complete oil-air passage systems, which are described in detail hereunder in this specification.